Means for photometering electric lamps.



' H. S. DUNNING & W. G. HOUSKEEPER. MEANS FOR PHOTOMETBRING ELECTRICLAMPS, APPLICATION FILED MAY 16, 1910.

6 SHEETS-SHEET l.

Percenf 0f rafcd ra/f urrenf.

I. 40 W0 #5 Cand/e WITNESSES: u F193 I VENTOR; mm m, Q5. CYOLM I WATTORNEY H. S.DUNNING & W. G. HOUSKEEPER.

MEANS FOR PHOTOMETERING ELECTRIC LAMPS.

APPLICATION FILED MAY 16, 1910.

1,057,415. Patented Apr.1,19 13.

6 SHEETSr-SHEET 2.

50715 FOR 2.5 1442c. MfTAL/ZED LAMPS PHOTOMETE RED AT 20 CANDLE POWER.

WITNESSES:

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H. s DUNNING & W. G. HOUSKEEPER.

MEANS FOR PHOTOMETERING ELECTRIC LAMPS.

APPLIUATION FILED MAY 16, 1910.

1,657,415. Patented Apr.1,1913.

6 SHEETSSHBET 3.

WITNESSES: l VENTORS/ ATTORNE H. S. DUNNING & W. G.. HOUSKEEPER.

MEANS FOR PHOTOMETERING ELECTRIC LAMPSv APPLIOATION FILED MAY 16, 1910.

' Patented Apr. 1,- 1913.

6 SHEETS-SHEET 4.

30745 FOR 64- WHTT- l6 6.; 4.0 MP6. 637198011 LII/7P gvlzmoas .m

ATTORNEY filly. 5;

WITNESSES:

@Ho @S. QYQZM'M H. s. DUNNING & w." G. mmsmwmz. 1 MEANS FORPHOTOMETERING ELECTRIC LAMPS.

APPLICATION rum mxm, 1910 Patented Apr. '1, 1913.

6 SHEETS-SHEBT 5.

ATTOR N EY ill? HERBERT S. DUNNING, OF NEW DORE, NEW

YORK, AND WILLIAM Gr. HOUSKEEPER,

0F PHILADELPHIA, FENNSYLVANIA, ASSIGNORS 10 VJESTINGHOUSE LAMP COM--PANY, 1i. CORPORATION OF PENNSYLVANIA.

MEANS FOR PEIOTQMETEBING ELECTRIC LAMPS.

To all whom it may concern:

Be it known that we, l-l'unnice'r S. DUN NING and WiLLIAM G. Honsunncna,citizens of the United States, and residents, respectively, of NewDOI'P, Staten island, in the county of Richmond and State of New York,and of Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented a new and useful ,llniprovo ment in lVlQtlDSfor Phottnnetering Electric Lamps, of which the following is aspecification.

Our invention relates to methods of and means for photometering ordetermining the ratings of incandescent lamps, and it has for its objectto provide method and means for such purpose which. shall. be She pleand etl'ective in operation and capable of giving direct indications ofI electrical values or ClIEtK'QLC'tGPlStlCS of lamps which it hasheretofore been possible to obtain or determine only indirectly or bylaborious computations.

g The invention consists in obtaining direct and independent indicationsof the voltage and currentot a lamp at given canoe power, and incombining the said indicationsto obtain a direct indication of certainval.- ues or characteristics of the lamp upon a chart, especiallyprepared for the purpose, and having lines or a calibration determinedby the characteristic curves of lamps of the kind under test. In themeasurement of the voltage and current of the lamp under test, aninstrument which is similar, in construction, to that disclosed inPatent N o. 791,?85

ma he em ilo ed the chart men the dial plate being; provided withcalibration lines which aredetermined from the characten istie curves oflamps ot the kind under test and adapted to "give the i. formationparticularly desired with reference the lamp under test. lly the use ofthe proper chart in connection with the said instru ment, it is possibleto o-htain a direct indication of the amperes actually consumed lay alamp undcr test, the actual voltage between its terminals, the actual.number of watts it consumes, the actual numher of watts consumed percandle power of lit-5h t, the voltage -whicl1 the lamp will operate atany do ed ellicicncy, when measured in watts cone suine 'l tierfcandlcpower of light, the current required the lamp, under operation atSpecification of Letters Patent.

certain of tie.

any desired efiiciency, when measured in the watts consumed per candlepower of light, the candle power vhich the lainp will give, underoperation at any desired efficiency, when measured in watts consumed percandie power of: light, or the total number of watts which a lamp willconsume, under op oration at any desired ettlciency, when measured inwatts per candle power of light.

The dials may also he so arinngedthatsevoral of these items ofinformation may he obtained from a single instrument. The manner inwhich these values may be ohtaincd will he explained in connection withthe. acctmipanying drawings, Figure 1 of which. is a diagrammatic viewoi the complete apparatus for practising the invention. Fig/2' is achart for an instrument which is "adapted to give direct-indications ofthe total number of watts actually consumed by the lamp under test, andoif its actual Incasured eiiiciency in watts consumed per candle powerof light. Fig. 3 represents the characteristic curves of anincandescent, lamp which was used in determining the calihration of thecharts of Fig. t, and which is useful in explaining the same. i Fig. 4rep resents the dial plate of an instrument by means '01": which directindications niay be olotaincd of the voltage at whicha lamp will operateat a given etliciency, when measured in watts consumed per candle powerof light, irrespective of the voltage and elliciency at which the lampoperates during the test. it also permits of olot-aininoa directindication of the eliicicncy at which a lamp operates during the test.Fig. 5 represents the dial plate oi an instrumentby means of which adirect indication may. be obtained oif ihe cliiclency at which a'lamp'operates during the test, and, also, whereby a direct indication may heobtained of the current required by. the lamp in order to cause it tooperate at a desired or given etliciency. Fig. tlrcprescnts the dialplate of an instrument whereby a direct indication may be obtained ofthe total number of watts that will be consumed loy ada mp, and also oiits candle power, when operated at a given elliciency measured in wattsconsumed per-ca ndle power of light. igfll' represents the dial plate ofan instrument whereby a direct indication may he obtained as to whetheror not a lamp, when operated at .Hatenteill Apr. it, i913.

Applicationfilcd May 16, 1910. Serial No. 561,735.

ments and corresponding independent point ers 4. and 5 that move inparallel planes and in intersecting paths over a common dial plate 6.The dial plate is provided with volt and ampere scales, respectively,beneath the free extremities of the voltmeter and ammeter pointers.Between the volt and ampere scales is a triangular chart that iscalibrated in. accordance with the purpose for which the instrument isemployed and with the kind of lamps to be tested. The 'dial platerepresented by Fig. 2 is adapted to be used in an instrument employedfor making measurements upon metallized carbon-filament lamps having anominal ratin g of twenty candle powerand an efficiency of two andone-half watts per candle power. By means of this chart, as beforestated, the total number of watts actually consumed by a lamp, whilebeing tested, may be directly determined, and also the actual etliciencyot' the lamp, as operated during the test, when measured in the numberof watts consumed thereby per candle owcr of its light. Theseindications are ma e upon the chart at the intersection of the voltmeterand ammctcr pointers, and, at the extremities of the pointers, thevoltage and current of the lamp are also indicated. The calibration ofthe chart, for the total number of watts consumedby the lamp, isobtained or determined by multiplying together-the "olta'ge and currentindications at the extremities of the instr lment pointers for any givenmeasurement, and locating the corresponding wattage value upon the chartdirectly beneath the intersection of the pointers. Since the lamp undertest is constantly maintained at twenty candle powe the eiiiciency oithe lamp, when measured in watts consumed per candle power of light, maybe determined by dividing the total number of watts consumed by twenty.Thus, the line upon the chart which represents a total wattage of eightyalso represents an efficiency of tour watts per candle power. From thisbrief description, the manner in which all of the linesor points uponthe triangular chart are determined becomes obvious.

Theleurves of Fig. 3 were obtained by actual measurement from lamps andby comthe. test.

putations from such measurements, and'they respectively represent.- thepercentage of variation of the'voltage, current, wattage and candlepower of a tungsten filament lamp, having a nominal rating of onehundred watts, eighty candle power and an etticicncy of 1.25 watts percandle, with variations in the number of watts consumed by the. lamp percandle power of its light. These curves provide means for readilydetermining the percentage of change. which must be effected in thevoltage, current, wattage or candle power of a lamp, when operating at agiven etficiency, as measured in watts consumed per candle power oflight, in order to cause the same to operate at any other desiredefficiency, as measured in watts consumed per candle power of light.These curves were employed in determining the calibration of the chartupon the dial plate of Fig. 4, which adapted to be employed in makingmeasurements upon lamps of the kind of which Fi 3 represents thecharacteristic curves. urves similar to those of Fig. 3 were alsoemployed in the calibration of the charts upon the dial plates of Figs.5, 6 and 7.

The dial plate represented by Fig. 4 is intended for use in instrumentsadapted to make measurements upon tungsten-filament lamps having anominal rating of one hundred watts, eighty candle power and anefficiency of 1.25 watts per candle power, and the manner in which thechart upon the said dial plate was determined will now be given. Theapproximately horizontal circular lines or arcs, which represent-theefiiciency of a lamp under test, in watts consumed per cans dle power oflight, tire determined by multiplying together the voltage and currentindications at the extremities of the volt- I meter and ammet-r pointersfor any given positions thereof, and dividing this product by eighty,which is not only the nominal candle power of the lamp under test butthat at which it is actually maintained during This quotient gives onevalue of the watts consumed per candle power, and a point correspomlingto this value is applied to the chart directly beneath the intel-sectionot the voltmeter and ammeter pointers. In this manner, a large number ofpoints upon the chart are determined and curves are drawn through suchpoints as represent the same values.

A specific example of the manner of locating a single point upon thelines upon the chart that represents the voltages at which lampswill'consume 1.25 watts per candle power will. fully explain the mannerin which all of the said lines are determined. It the voltage of thelamp under test is 112.8 and its current .922 of an ampere, the actualnumber of watts cons une'd by the lamp is 104. The efficiency o th lampis eliiciency of 4t watts per candle nver.

direct indications nouns-is 1% divided by 80, or 1.3 watts per candlepower. Referring nowto the voltage curve of Fig. 3, it will be foundthat the voltage of a lamp of the particular kind under test, whenoperating at 1.3 watts per candle power, is approximately 98% oil thevoltage at which the lamp will operate at an efficiency of 1.25 wattsper candle power. Dividing 112.8 by .98, it is found that, if the lampis operated at a voltage of US, it will give an eiliciency of M25 wattsper candle power. It will now he noted that the voltmeter and anu'neterpointers,- when respectively indicating 112.8 volts and .922

amperes, intersect upon the arc representmg 1.3 Watts per :andle power,and that said intersection occurs upon the line representing 1.15 volts,which is the same as the above calculated voltage of 115. The

115 volts are up meaning of this is that, it

give an eiliciency plied to the lamp, it will of 1.25 watts per candlepower. ll lany points upon the chart were located in this manner, andcurves were drawn tinnigh the points representing the same values. theuse of an instrument having a dial plate like that shown in Fig. i, thevoltage, current and efficiency of the lamp under test at its nominalcandle power i'nay be readily determined, aswell as the voltage at whicuthe lamp will give an eflicienc'y oir'. watts per candle power. Thisinformation has heretofore been derived only by a series of computationssimilar to that resorted to in determining the location of a singlepoint upon the chart of the dial plate of 4-, and, since it isotter-highly desirable ti at lamps should be rated and, marked with thevoltage at which they will give a certain efficiency, the utility of thepresent instrument is readily apparent, because it gives values whichcould heretofore be arrived at only indirectly and by computation.

The dial plate of Fig. 5 i strument adapted for use in. coi'inectionwith carbon-filament lamps having a nominal rating of 6% watts, Titicandle power and an 'ihe calibration of the chart upon the dial platewas determined in a manner similar to that described for the chart ctFig. i, by using; the characteristic current curve, instead of thecharacteristic voltage curve, lamps of the kind under test, thecharacteristic current. curve being similar to that of Fig. 3. Ofcourse, when this dial plate is enoployed, lamps are usually of theseries typeyas it is with this type of lamp thatit desirable to know thecurrent valueat which the lamp will have an efficiency of a givennuinher of s that oi an inwvatts per candle power, in order-that theThus, in y candle power,

will have a given efiiciency, irrespective of the measured voltage andcurrent when'the lamp is operating at its nominal candle power, but alsothe total number of ,Watts which the lamp-will consume and its eandlepowe at a given elilciency. The chart upon the dial plate of 6 isadaptedto give such additional. information, this dial-plate beingintended for use in instruments eulployed in making measurements uponcarbon-filament lamps having a nominal rating of 56 watts, 16 candlepower and an elliciency of watts per candle power. In order to determinethe location of any particular point upon this chart, the voltage andcurrent indications, respectively, at the extremities of the voltmeterand amineter pointers are first multiplied together and the productdivided by 16, which is the nominal candle power of the that at which,it is maintained during the test. This quotient represents theeihci'ency ot the lamp at 16 candle power, and, then, by referring tothe characteristic watt and can dle power curves (similar to those ofFig. 3) of lamps of the same kind as that under test, the percentage ofchange in the wattage and candle power, in order to cause the lamp tooperate at an efiiciency of 3.5 watts per candle power, can be readilydetermined. A point corresponding to the value thus determined is placedupon the chart directly beneath the intersection of the instrumentpointers, and a large numberoi' the-points are determined in the samemanner, after are drawn through points repwhich curves resenting thesame values. Thus, in order-to determine the candle power of a lamp and.

the nunioerot' watts it will consume when operating at an eiiiciency of3.5 watts per it is, only necessary to main tain the lamp at 16 candlepower and note upon the chart the point of intersection of the voltmeterand amnieter pointers.

in rating or photometering lamps, it is often desirable to select from abatch of lamps those that vary only within a definite from a givenwattage and candle percentage power, at a certain voltage, and an instrwnient having a dial plate like that of Fig. 7 provides a ready means forvmaking such selections. The dial plate is adapted for use ininstruments employed to make measurements upon carbon-filament lampshaving a nominal rating of 56 watts, 16 candle power and an effic1encyof 3.5 watts per candle power. The chart upon this dial is provided withlines representing voltages at which the lamps will operate at an eficiency oil-3.5 watts per candle power. It is also provided with severalsets of concentric polygons bearing certain voltage designations. Theinner polygon, having any particular voltage designation, is of suchsize and shape, that, it the instrument pointers intersect above it,when the lamp is maintained at 16 candle power, the lam will consumewithin 2%% of 56 watts an will give within 25 of 16 candle power whenthe lamp is operated at the voltage by which the polygon is designated.If the intersection 'of the pointers occurs over the larger polygon ofany particular voltage designation, the lamp will consume with n 75% of56 watts and will give within 7-% of 16 candle power when the voltagecorresponding to that by which the polygon is designated is applied tothe lamp. If the intersection of the instrument pointers occurs outsideof the polygons, the point of intersection will occur upon some one ofthe lines designating the voltage at which the lamp will give anetticicncy of 2};- watts per candle power, and the lamp may then bemarked with such voltage and eflicicncy, Thus, this chart provides meansfor making a ready selection of lamps which will operate within certainspecified limits and also for properly rating such lamps as do not comewithin the designated limits.

While many modifications of the invention have been illustrated anddescribed, it will be understood that the invention is not limited tosuch specific applications but that it is susceptible of use under otherconditions and for other purposes, the essential feature of theinvention consisting in providing the dial plate of the instrument witha chart or calibration that is determined both by the actualmeasurements taken during the test and by the known characteristics ofthe lamps or other devices under test.

We claim as our invention 1. The combination with a photometer forelectric lamps, of a measuring instrument associated with the lamps andhaving a plurality of independent indicating mem bers that are movablein intersecting paths, and a chart upon which the said members effect acombined indication, the said chart being provided with marksrepresenting values determined by the characteristics of lamps of acertain kind.

2. The combination with a photometer for electric lamps, of an ammeterand a voltmeter having indicating devices movable in intersecting paths,and a scale or chart provided with lines or other marks representing oneor more electrical values at which lamps of a certain kind will consumea given number of watts.

3L The combination with a photometer.

for electric lamps, of an ammeter and a voltmeter having indicatingdevices movable in intersecting paths, and a scale or chart providedwith lines or other marks representing one or more electrical values atwhich lamps of a certain kind will consume a given number of watts percandle power.

4. The combination with a photometer for electric lamps, of an ammet-erand a voltmeter having'in'dicating devices movable in intersectingpaths, and a scale or chart provided with lines or other marksrepresenting amperes at which lamps of a certain kind will consume agiven number of'watt-s per candle power.

5. The combination with a photometer for electric lamps, of an ammeterand a voltmeter having indicating devices movable in intersecting paths,and a scale or chart provided with lines or other marks representingvalues at which lamps of a certain kind will consume a given number ofwatts per candle power.

6. The combination with a photometer for electric lamps, of an ammeterand a voltmeter having indicating .devic'es movable in intersectingpaths, and a scale or chart provided with lines or other marksrepresenting the numbers of watts consumed per candle power by the lampsbeing photometered.

In testimony whereof, we have hereunto subscribed our names this 2nd dayof May,

ll. S. DUNNTNG. WILLIAM G. HOUSKEEPER. Witnesses:

Cr-IAnLns E. KELLY, C. W. YOULNGIIOLM.

